From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: deepak1556 <hop2deep@gmail.com>
Date: Fri, 29 Jul 2022 00:29:35 +0900
Subject: chore: modify chromium handling of mouse events
￼
This patch does the following:

1. When Windows Control Overlay is enabled, it allows chromium to handle synthetic mouse events generated for touch
actions in the non-client caption area.
2. It calls HandleMouseEvent on the delegate earlier in HandleMouseEventInternal, so that Electron can selectively disable
draggable regions to allow events to propagate to the underlying renderer.￼

diff --git a/ui/events/event.h b/ui/events/event.h
index e002d4011ddd1dd26f7c412a337221d57e9e9bd4..7ac7313f3af5145bc7513f22c02a8e099e7abdea 100644
--- a/ui/events/event.h
+++ b/ui/events/event.h
@@ -583,6 +583,9 @@ class EVENTS_EXPORT MouseEvent : public LocatedEvent {
 
   const PointerDetails& pointer_details() const { return pointer_details_; }
 
+  bool is_system_menu() const { return is_system_menu_; }
+  void set_is_system_menu(bool is_menu) { is_system_menu_ = is_menu; }
+
   // Event:
   std::string ToString() const override;
   std::unique_ptr<Event> Clone() const override;
@@ -615,6 +618,8 @@ class EVENTS_EXPORT MouseEvent : public LocatedEvent {
 
   // Structure for holding pointer details for implementing PointerEvents API.
   PointerDetails pointer_details_;
+
+  bool is_system_menu_ = false;
 };
 
 class ScrollEvent;
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
index 94366475b7f9d128d8208de44d4d8a11096b146b..5867a8ae7e416ddc29a8a251dc6271009f3409db 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
@@ -1281,6 +1281,10 @@ void DesktopWindowTreeHostWin::HandleHeadlessWindowBoundsChanged(
   window()->SetProperty(aura::client::kHeadlessBoundsKey, bounds);
 }
 
+bool DesktopWindowTreeHostWin::HandleMouseEventForCaption(UINT message) const {
+  return false;
+}
+
 DesktopNativeCursorManager*
 DesktopWindowTreeHostWin::GetSingletonDesktopNativeCursorManager() {
   return new DesktopNativeCursorManagerWin();
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
index 286fcdf651131d231b07a52a53a1945c144c79ea..73d0729784e339b9abc20f7f22bccee1e0393c1c 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
@@ -264,6 +264,7 @@ class VIEWS_EXPORT DesktopWindowTreeHostWin
   void HandleWindowSizeUnchanged() override;
   void HandleWindowScaleFactorChanged(float window_scale_factor) override;
   void HandleHeadlessWindowBoundsChanged(const gfx::Rect& bounds) override;
+  bool HandleMouseEventForCaption(UINT message) const override;
 
   Widget* GetWidget();
   const Widget* GetWidget() const;
diff --git a/ui/views/win/hwnd_message_handler.cc b/ui/views/win/hwnd_message_handler.cc
index d29cdda6208576f1be3f5a6857fc068bb1397b23..93961374b6ecaf9a169dd8a02c235387e8cad609 100644
--- a/ui/views/win/hwnd_message_handler.cc
+++ b/ui/views/win/hwnd_message_handler.cc
@@ -3123,15 +3123,19 @@ LRESULT HWNDMessageHandler::HandleMouseEventInternal(UINT message,
       SetMsgHandled(FALSE);
     // We must let Windows handle the caption buttons if it's drawing them, or
     // they won't work.
+    bool simulate_mouse_event_for_caption = false;
     if (delegate_->GetFrameMode() == FrameMode::SYSTEM_DRAWN &&
         (hittest == HTCLOSE || hittest == HTMINBUTTON ||
          hittest == HTMAXBUTTON)) {
-      SetMsgHandled(FALSE);
+      simulate_mouse_event_for_caption =
+          delegate_->HandleMouseEventForCaption(message);
+      if (!simulate_mouse_event_for_caption)
+        SetMsgHandled(FALSE);
     }
     // Let resize events fall through. Ignore everything else, as we're either
     // letting Windows handle it above or we've already handled the equivalent
     // touch message.
-    if (!IsHitTestOnResizeHandle(hittest))
+    if (!IsHitTestOnResizeHandle(hittest) && !simulate_mouse_event_for_caption)
       return 0;
   }
 
@@ -3152,6 +3156,7 @@ LRESULT HWNDMessageHandler::HandleMouseEventInternal(UINT message,
     // handle alt-space, or in the frame itself.
     is_right_mouse_pressed_on_caption_ = false;
     ReleaseCapture();
+
     // |point| is in window coordinates, but WM_NCHITTEST and TrackPopupMenu()
     // expect screen coordinates.
     POINT screen_point = CR_POINT_INITIALIZER_FROM_LPARAM(l_param);
@@ -3159,7 +3164,17 @@ LRESULT HWNDMessageHandler::HandleMouseEventInternal(UINT message,
     w_param = static_cast<WPARAM>(SendMessage(
         hwnd(), WM_NCHITTEST, 0, MAKELPARAM(screen_point.x, screen_point.y)));
     if (w_param == HTCAPTION || w_param == HTSYSMENU) {
-      ShowSystemMenuAtScreenPixelLocation(hwnd(), gfx::Point(screen_point));
+      LONG message_time = GetMessageTime();
+      CHROME_MSG msg = {hwnd(),
+                        message,
+                        w_param,
+                        l_param,
+                        static_cast<DWORD>(message_time),
+                        {CR_GET_X_LPARAM(l_param), CR_GET_Y_LPARAM(l_param)}};
+      ui::MouseEvent event(msg);
+      event.set_is_system_menu(true);
+      if (!delegate_->HandleMouseEvent(&event))
+        ShowSystemMenuAtScreenPixelLocation(hwnd(), gfx::Point(screen_point));
       return 0;
     }
   } else if (message == WM_NCLBUTTONDOWN &&
diff --git a/ui/views/win/hwnd_message_handler_delegate.h b/ui/views/win/hwnd_message_handler_delegate.h
index fde18715e33ee67f64740ebda7c641954360483c..cf1ea75f8e9dd1d95045736959c4f3ca1a27a1ab 100644
--- a/ui/views/win/hwnd_message_handler_delegate.h
+++ b/ui/views/win/hwnd_message_handler_delegate.h
@@ -255,6 +255,10 @@ class VIEWS_EXPORT HWNDMessageHandlerDelegate {
   // Called when the headless window bounds has changed.
   virtual void HandleHeadlessWindowBoundsChanged(const gfx::Rect& bounds) = 0;
 
+  // Called when synthetic mouse event is generated for touch event on
+  // caption buttons.
+  virtual bool HandleMouseEventForCaption(UINT message) const = 0;
+
  protected:
   virtual ~HWNDMessageHandlerDelegate() = default;
 };
